On Thu, Mar 30, 2023 at 05:12:46AM -0600, Felipe Contreras wrote: > IFS=, > str='foo,bar,,roo,' > printf '"%s"\n' $str > > There is a discrepancy between how this is interpreted between bash > and zsh: in bash the last comma doesn't generate a field and is > ignored,
... which is correct according to POSIX (but not sensible). > in zsh a last empty field is generated. Initially I was going > to report the bug in zsh, until I read what the POSIX specification > says about field splitting [1]. You seem to have misinterpreted whatever you read. https://mywiki.wooledge.org/BashPitfalls#pf47 Unbelievable as it may seem, POSIX requires the treatment of IFS as a field terminator, rather than a field separator. What this means in our example is that if there's an empty field at the end of the input line, it will be discarded: $ IFS=, read -ra fields <<< "a,b," $ declare -p fields declare -a fields='([0]="a" [1]="b")' Where did the empty field go? It was eaten for historical reasons ("because it's always been that way"). This behavior is not unique to bash; all conformant shells do it.
